The Joint Milli-Arcsecond Pathfinder Survey (JMAPS) was an all-sky, bright-star astrometric and photometric cataloging mission of the Department of the Navy (DoN) that was jointly undertaken by the Naval Research Laboratory (NRL) and the United States Naval Observatory
(USNO). The program was executed from 2009 until December 2011 when it was discontinued due to budget cutbacks within the DoN. Some instrument development work is still on-going.

The primary goal of the mission was to update and modernize the current bright star catalogs in order to meet future national security space needs and requirements of the Department of Defense (DoD), NASA, and other developers of satellites for purposes of attitude determination. The JMAPS mission was designed to provide a highly accurate (1 milli-arcsecond) catalog of astrometric and photometric parameters such as stellar position, brightness and color covering the entire sky, with sensitivity sufficient to provide suitable guide stars required by any subsequent mission. This was to be accomplished using a dedicated astrometric telescope flown on a small satellite
(micro-satellite) in a sun synchronous terminator orbit that was scheduled to be launched in 2015. Over the course of the three-year primary mission the JMAPS instrument was going to image the complete sky multiple times to high precision. The resulting image data would have been processed on the ground using algorithms developed by the USNO to provide highly accurate stellar position, proper motion, parallax and photometric data. Following the measurement phase of the JMAPS mission, those data would have been used to generate the final Bright Star Catalog. The update would have improved the position accuracy of known bright stars for the 2015 epoch to the level of 1 milli-arcsecond (5 nano-radians) for stars up to absolute magnitude 12.

JMAPS spacecraft on orbit (Credit: U.S. Naval Observatory)

The JMAPS Missions Operation Center (MOC) was to be operated by the NRL, which also had the responsibility for developing the space and launch segments of the JMAPS mission, while the USNO was responsible for developing and operating the Data Processing and Analysis Center (DPAC) and Science Payload Operations Center (SPOC) of the Ground Segment. The DPAC and SPOC were to provide mission planning, data processing, data management, data analysis, and generation of the final catalog for the JMAPS mission. CPI was providing software architecture, design, and development support for the DPAC and SPOC at the USNO. Our software professionals worked with the USNO scientists to develop the various data processing pipelines and infrastructure software. Development was occuring throughout the mission, as algorithms were refined with better understanding of the data. CPI software professionals implemented and maintained the data management system and processing frameworks.

NRL's primary responsibility for the JMAPS program was to construct a satellite that has two major elements designed to support the overall mission. One element was the design architecture of the spacecraft bus. The second element was the lightweight, high performance, and state-of-the-art instrument, which was to be constructed with silicon carbide power optics, silicon mirrors, and a silicon carbide structure to minimize mass and maximize performance. The instrument utilizes hybrid complementary metal oxide semiconductor (CMOS) detectors to support the necessary performance and readout capability for JMAPS. Upon launch, the JMAPS spacecraft was to observe stars over 37 months. The data collected on board the spacecraft was to be transmitted to the mission operations center located at the NRL Blossom Point Tracking Facility several times a day.

JMAPS spacecraft concept (Credit: U.S. Naval Observatory)

After the data was collected at Blossom Point, the information was to be transferred to the USNO's SOC where mission scientists would monitor the instrument, and process and analyze the data providing mission planning information back to NRL. The final step in the process was to be the generation and delivery of the full star catalog to the Navy, which was to occur one year after the end of the flight mission.

JMAPS would have satisfied emerging requirements to meet future needs for high accuracy sensors and weapons systems by enabling the nation to conduct operations from space that are not technically feasible with current levels of accuracy. Whether using imagery to plan precision strikes or monitoring developing storms to assist in humanitarian relief, U.S. military forces rely on space as an enabler. Satellites and weapons across the spectrum of warfare utilize key satellite technologies like star catalogs to ensure accuracy and position. An advanced star catalog and technology would also have benefited other users, including the commercial satellite community and NASA. Potential NASA applications of these new, advanced capabilities include improving the ability to navigate within our solar system and enabling the discovery of planets outside our solar system.